Tens of thousands of books have been written on leadership and there are several academic journals devoted entirely to the subject, including The Leadership Quarterly and The Journal of Leadership and Organizational Studies. Perhaps the most definitive review and integration of the leadership literature was Bass and Stogdill’s 1,200-page Handbook of Leadership, which was published in 1990 (and still does the best job of making sense of the literature, for my money). And if you really want a long book on leadership, you can get the four-volume Encyclopedia of Leadership, which at 2,120 pages weighs in at 15 pounds, and costs a whopping $800. Clearly, the task of reviewing the leadership literature — and acting on it as leader — isn’t to understand it all (that is impossible), but to develop a point of view on the few themes that matter most.

In my reviews of the writings and research, I kept bumping into an old and popular distinction that has always bugged me: leading versus managing. The brilliant and charming Warren Bennis has likely done more to popularize this distinction than anyone else. He wrote in Learning to Lead: A Workbook on Becoming a Leader that “There is a profound difference between management and leadership, and both are important. To manage means to bring about, to accomplish, to have charge of or responsibility for, to conduct. Leading is influencing, guiding in a direction, course, action, opinion. The distinction is crucial.” And in one of his most famous lines, he added, “Managers are people who do things right and leaders are people who do the right thing.”

Although this distinction is more or less correct, and is useful to a degree (see this recent interview with Randy Komisar for a great discussion of the distinction), it has unintended negative effects on how some leaders view and do their work. Some leaders now see their job as just coming up with big and vague ideas, and they treat implementing them, or even engaging in conversation and planning about the details of them, as mere “management” work.

Worse still, this distinction seems to be used as a reason for leaders to avoid the hard work of learning about the people that they lead, the technologies their companies use, and the customers they serve. I remember hearing of a cell phone company CEO, for example, who never visited the stores where his phones were sold — because that was a management task that was beneath him — and kept pushing strategies that reflected a complete misunderstanding of customer experiences. (Perhaps he hadn’t heard of how often Steve Jobs drops in at Apple stores.)

That story is typical. “Big picture only” leaders often make decisions without considering the constraints that affect the cost and time required to implement them, and even when evidence begins mounting that it is impossible or unwise to implement their grand ideas, they often choose to push forward anyway .

I am all for dreaming, Some of the most unlikely and impressive things have been done by dreamers. But one characteristic of the dreamers I respect — Francis Ford Coppola, Steve Jobs, folks at Pixar like Ed Catmull and Brad Bird — is that they also have remarkably deep understanding of the industry they work in and the people they lead, and they are willing to get very deep into the weeds. This ability to go back and forth between the little details and the big picture is also evident in the leaders I admire most who aren’t usually thought of as dreamers. Anne Mulcahy’s efforts to turn around Xerox were successful in part because of her in-depth knowledge of the company’s operations; she was very detail-oriented during the crucial early years of her leadership. Bill George, one of Jim Collins’ level 5 leaders, told me that, in his first nine months as CEO of Medtronic (a medical device company), he spent about 75% of his time watching surgeons put Medtronic devices in patients and talking with doctors and nurses, patients, families, and hospital executives to learn the ropes.

I guess this is one of the themes that I have written about before, especially in The Knowing-Doing Gap (with Jeff Pfeffer). But it is bothering me more lately, as I’ve had some conversations with project managers who have been assigned tasks by naive and overconfident leaders — things like implementing IT systems and building software. When they couldn’t succeed because of absurd deadlines, tiny staffs, small budgets, and in some cases, because it simply wasn’t technically possible to do what the leaders wanted, they were blamed. Such sad tales further reinforce my view that thinking about what could exist, and telling people to make it so, is a lot easier than actually getting it done.

I am not rejecting the distinction between leadership and management, but I am saying that the best leaders do something that might properly be called a mix of leadership and management. At a minimum, they lead in a way that constantly takes into account the importance of management. Meanwhile, the worst senior executives use the distinction between leadership and management as an excuse to avoid the details they really have to master to see the big picture and select the right strategies.

Therefore, harking back to the Bennis theorem I quoted above, let me propose a corollary: To do the right thing, a leader needs to understand what it takes to do things right, and to make sure they actually get done.”

When we glorify leadership too much, and management too little, there is great risk of failing to act on this obvious but powerful message.

Robert Sutton is Professor of Management Science and Engineering in the Stanford Engineering School, where he is co-director of the Center for Work, Technology, and Organization, cofounder of the Stanford Technology Ventures Program, and a cofounder and active member of the new “d.school.” His new book, with Huggy Rao, is Scaling Up Excellence: Getting To More Without Settling For Less.